Apparatus for operating cylinder printing presses



Jan. 5, 1937. R. STUSSI 2,066,429

APPARATUS FOR OPERATING CYL INDER PRINTING PRESSES 4 Filed March 16, 1931 5 Sheets-Sheet l Z a 3A \\'C 1 l Irv enter Rudvz 166 vzey.

Jan. 5, 1937. R. STUSSI 2,066,429

APPARATUS FOR OPERATING CYLINDER PRINTING PRESSES Filed March 16, 1951- 3 Sheets-Sheet 2 Jan. 5, 1937. R. STUSSI 2,066,429 APPARATUS FOR OPERATING CYLINDER PRINTiNG PRESSES Filed March 16, 1931 5 Sheets-Sheet 5 jl zr ezzivr Kmzof Sta? ssa Patented Jan. 5, 1937 UNITED STA'i'E r QFEECE Rudolf Stiissi, Glarus, Switzerland, assignor ta Druckmasehinen Alrtiengesellschaft,

Switzerland Glarus,

Application March 16, 1931, Serial No. 523,095 In Germany December 19, 1930 3 Claims.

This invention relates to improvements in cylinder printing presses with the impression cylinder revolving continuously in one direction.

In cylinder printing presses of this kind, the so-called single-revolution machines, and also two-revolution machines, the diameter of the impression cylinder is usually made as great as the length of travel of the form bed requires for this to-and-fro movement, including the reversal, the

impression cylinder of the single revolution machines executin one complete revolution for each complete reciprocation of the-form bed, whereas the impression cylinder of the two-revolution machines executes one complete revolution for each forward movement and for each return movement. In both cases the form bed is driven during the to-and-fro movement constantly at the speed of the cylinder.

Now it is known, however, that good printing work can only be produced up to a certain maximum speed. If this speed limit is exceeded, the inking of the form becomes defective, and the paper does not have time enough for the reception of the ink and the registering is bad, because the feeding of the sheet has to be effected to the impression cylinder revolving at a high speed. The machines mentioned were frequently capable of running at a rather high speed, but owing to the difficulties in printing technology the utilization of the full speed of the machines is not possible.

By the improvement according to the invention these disadvantages are obviated, and a subsequently higher printing output than has hitherto been attained with cylinder printing presses having a continuously revolving impression cylinder is reached, but the quality of the printing remains the same.

The invention consists essentially of the fact that by diminishing the diameter of the impression cylinder the peripheral speed of the impression cylinder is diminished, but maintaining constant the length of the impression receiving segment on the cylinder for a given size of sheet, and that the return of the form bed is effected by a greater speed.

Since in consequence of the diminution of the diameter of the impression cylinder, with a constant size of the impression receiving segment on the impression cylinder, the operations required in printing, such as taking over the sheet from the feeding table, inking the form before printing and the printing operation itself, extend over a larger portion of the cylinder periphery than hitherto, the form bed must according to the invention be moved at a higher speed during the return than during the printing stroke.

Since according to the invention the abovementioned operations required during the printing stroke, and also the removal of the printedv sheet, are effected at the reduced peripheral speed of the smaller impression cylinder, and therefore more favourable conditions are provided for these operations, an increase in the speed of revolution may at once be effected, and therefore an enhanced output in proportion to the diminution in the diameter of the impression cylinder, or, in other words, according to the method of this invention, definite printing work can still be carried out at substantially higher speeds of revolution of the cylinder than in machines of the kind hitherto known, but with the same quality of printing, or printing work can be carried out at a high speed of revolution of the cylinder which would only admit of being executed in machines of the kind hitherto known at substantially lower speeds.

Besides the increase in output directly attainable by diminishing the diameter of the impression cylinder, this increase being approximately. proportional to the value of the decrease in diameter, a further increase in output is yielded with the method according to the invention owing to the fact that the form bed, in consequence of the diminution in the diameter of the impression cylinder, has a substantially shorter path to traverse for printing paper of the same length,

and therefore can be returned earlier than in the machines hitherto known, as will hereinafter be shown.

The various speeds of the form bed may be for instance obtained from a crank drive in combination with a rack gear, in such a way that the form bed, owing to the control of a rack slidable in the machine frame, receives a uniform speed during the printing stroke, agreeing with the peripheral speed of the reduced impression cylinder, and receives a greater speed during the return stroke.

A cylinder printing press according tothe invention is illustrated by way of example in the accompanying drawings, which relate to a sin gle-revolution machine. In these drawings,

Figure 1 shows diagrammatically in longitudinal section through the upper part of the machine the parts of a single revolution machine that are concerned.

Figures 2-5 show the driving mechanism of the press illustrated in Fig. 1, these figures showing various positions during theprinting stroke and the returnstroke of the form bed; and

'j: 'Figure 6 showsa movement and speed diagramior the form'be-d. r

at a constant speed; The impression. cylinder, as Figure 1 shows, is i V 1 The impressioncylinder in the usual manner abovethe formgbed. 2, is

driven from a shaft l6, journalled'in the ma- ,chine frame. This shaft has for this purpose at each'of its outer ends a pinion I6 which meshes" with an intermediate wheel l'l. meshes'withia' toothed'wheel l8 connected with the impression cylinder I: and rotates the former per cent. smaller'indiameter than the impression cylinder indicated in dotted lines in l the drawingsand marked a, such aswouldihith- -erto have i been employed in single-revolution 1' 1 machines for paper of the same size. In consesion cylinder l the operations requiredforjthe quence of the reduced diameter of the impresprinting stroke extend over 'a larger portion of V 'the cylindrical surface than hitherto,- that is, over more -,than'180. On this ground the impres )sion cylinder! must revolve during the printing stroke through'angle a (Figure :1) as contrasted with the large impression cylinder hitherto used,

' which 'onlyexecuted half a revolution during the printing stroke. r

In consequence "of the '''diminution of .20 per cent, selected'by way of example, in the diam-' ,eter of the impressionlcylinder; the'peripheral speed'of the impression cylinder for the same r angular velocity is 20 percent; less. In order to' provide the same relationships or :workingcondi tions as in thecase of the largeimpres'sioncyh 'inder hitherto used, the speed of revolution-"0f the impression :cylindermay be increased by 20 J per -cent wherebya 20 per cent. increase of'outputis'o-btained, with the same quality of printing as in the case of. the large cylinder hitherto used. r

d-uced diameter during the printing stroke is ,marked 1: in Figure 1. This path is shorter by the :amount x =th=an the distance that the form- ,bed would .have had to traverse in the case of ;the large impression cylinder hitherto used for paper of the same format. The shortening "amounts to -about :10'per' cent. :of the total path and yields a corresponding diminution in the time occupied by the printing stroke and return stroke, whichcorresponds to a further increase in output of about 10 per cent,

' In .a' two-revolution machine "such a great shortening of the path is not possible in consequence of the impression cylinder being only "half as large but the. essential advantages of the diminished peripheral'speed of the impression cylinder still come fully into play' in the printing technology of two-revolution machines. Ina two-revolution machine the impression cylinder would execute more than one. revolution during the printing stroke, .andgthe, remainder.

of the second revolution would remain forthe quicker return of theform'bed.

' 'In thesingle-revolution machine selected for i a the example of construction, the return of the form bed must take place during the remaining i I partrb' (Figure .1 of-a complete revolution of the impression cylinder. The return speed of the form bed must therefore be" correspondingly greater. For this purpose "the following arrangement is made.

LWhiOh'iS supported The latter.

moved to and fro, and during this movement it varying angular velocity:

The path that-the form bed 2 has to traverse int-he case of the impression cylinder l of re,-

To the under side of the form bed '2 is secured a rack 4, with which'a toothed wheel '3 meshes.

' The latter meshes at the same time with a rack 5 longitudinally displaceable in the machine frame l3. The toothed wheel 3 is freely'rotatable upon the pivot 1 to'which aconnecting .rod 1 is attached, the other end of whichis pivoted to a crankfi, which is secured upon a shaft 6 journalled in themachine frame. During the revolution of the cranki the toothed: wheel3 is rolls along the rack 5, the form bed traversing twice asigreat a pathas the crank. For the'drivw ing of the crank shaft 6? there is secured to the latter outside the side wall of the machine frame I 3 a toothed wheel 8,.with which theremeshes a' toothed wheel I9. The 'latteris mountedupon a special shaft I9 and supported eccentrically to the intermediate wheel 11; Thetwo toothed" 20 one'another for a purpose hereinafter described by means of .a. linkr2l,which is rotatably :inount I ed at one :end on a bolt on the toothed whcel V wheels'l'l and I9 are however connected with H and at the other .end one, 'bolt "22.5011 'ithe toothed wheel [9. The toothe'd wheels 18,1118, and 19 may for example be ofrthe :same pitch diameterjiso that to one revolution of the 'im- 'plet'e revolution 'also :of the crankshaft 6 In consequence of the mutually. eccentric posipression-cylinder :I there corresponds onenorming angular velocity. Since the toothed'wheel i 1'9 meshes with the toothedjwheelfl thecrank 6 h 140. The arrangement is also set in rotationiin the :same manner with such that while the toothed wheels 1| and and therefore the impression cylinder I iare executing .9

during the printing stroke :a rotation of-the magnitude of the angle Pa; (Figures '1 and .2') at the #centre, that :is, more than half a revolutiomthe toothed wheels "'I Sand 8, and-therefore the crank time. This 'ihalfjrevolution is e'xecuted at a. di-

minished angular velocity. During :therreturri-of Y the form bed .2; however, the toothed wheels N. V and 1-8 and the impression cytinder 2i pass through;

the remaining angle 11 to complete the entire rev- 16, execute exactlyyhalf a revolution in the same olution. During this time the toothed wheelsgl! I 7' and "8, and therefore the crank Y6, execute the other. half revolution at an accelerated angular velocity.

During the printing stroke 17 e speed of the form bed :2 mustof course completely agree with the constant speedof the impression cylinder -I.

"Since however the pivot 1 of the toothed wheel 3, which ispermanently in mesh with the form 'bed 2, executes inconsequence of the crank drive,

6, 1 non-uniform longitudinal movementsgthe movements must be harmonized "during the'printing stroke. j

Forthis purpose there is provided in the toothed wheel 8 'a cam groove :8 in which the engages a roller 9 rotatably mounted on a'lever 9 The roller-lever 9 is :secured to a shaft :10, V

journalled in the machine frame, upon which shaft, in aboutlthe longitudinal central axis of the machine, is secured control leverl-l l the. lower 'endof which is connected-by a link raw-1th I the rack 5.

The operations during one printing and one return stroke are as follows:-

The sheet lying upon the feeding table 23, Figure 1, is seized during the rotation of the impression cylinder I in a known manner by the grippers 24 thereof and carried along with them. A start may here be made from the position of the parts indicated in Figure 2. The form bed 2 is in the position of reversal for the printing stroke. The crank 6 is rotating in the direction of the arrow in Figure 2. By this means the form bed 2 is moved in the direction of the printing stroke until the racks I5 fixedly arranged on the long sides of the form bed 2 come into engagement with the toothed segments I4 secured to the sides of the impression cylinder I. The rack 5 is displaced during the printing stroke, in consequence of the shape of the cam groove 8 in such a way that the rotary movement of the toothed wheel 3, independently of the retarded longitudinal movement of its pivot I brings about a uniform movement of the form bed 2, in harmony with the uniform rotary movement of the impression cylinder I.

During the printing stroke the form 25 that has been inked on the foregoing return stroke (Figure 1) is again inked by means of inking rollers 21 supplied from an ink trough 2B in a known manner and thereupon the printing is completed.

Figure 3 shows that position of the parts which they occupy at about the middle of the actual printing period. Since the rack I5 remains in mesh with the toothed segment I4 on the impression cylinder I for the duration of the uniform movement of the form bed 2, an accurate agreement of the movements of the two printing organs during the printing operation is secured.

In the position of the parts according to Figure 4, the racks I5 are already out of engagement with the toothed segments I4 of the impression cylinder I, and the return of the form bed 2 is commencing.

During the reversing movements of the form bed 2 the racks I 5 do not mesh with the segments I4. The latter are therefore shorter than the part of the periphery of the impression cylinder which is needed during the printing stroke.

During the printing stroke the impression cylinder I has revolved through an angle corresponding to the angle a (Figures 1 and 2) at the centre, but the crank 6 has only rotated through During the return of the form bed 2 the crank rotates through a further 180. During this portion of the crank circle the form bed 2 is returned at a speed higher than the peripheral speed of the impression cylinder, the toothed wheel 3 rolling upon the rack 5, which is now stationary.

Figure 5 shows the form bed 2 at about the middle of its return path. The racks I 5 can run through underneath the impression cylinder without hindrance, since they do not come into engagement with the toothed segments I4.

During the return of the form bed the impression cylinder I rotates through the angle 1) (Figure 1) in completing one entire revolution. In passing through this residual part of the complete revolution of the impression cylinder the printed sheet passes with the diminished peripheral speed of the impression cylinder in known manner over the discharge cylinder 28 (Fig. 1) on to the delivery pile 29.

From the diagram of Figure 6 the variation in speed of the form bed will be seen. Upon the crank circle 0 traversed by the crank 6 the individual angles of rotation arising from the varying angular velocity are indicated by the numerals I) to 24, the numerals I] to I5 corresponding to the printing stroke, and the numerals I5 to 24 corresponding to the return stroke of the form bed. The diagram d, representing the movement aris ing from the rotation of the crank and the acceleration is altered at the portion 01 of the curve during the printing stroke by the displacement of the rack 5. The actual speeds of the form bed are indicated in the diagram by full lines. It will be seen therefrom that during the printing stroke the form bed receives a uniform retarded motion, as represented in the upper portion (2 of the curve, and during the return stroke is driven with a non-uniform and enhanced velocity represented by the lower part d of the curve. The distance e in the upper portion d of the curve corresponds to the part of the path of the form bed upon which the printing takes place. To the points II, III, IV and V of the curve there correspond the positions of the form bed according to Figures 2, 3, 4, and 5.

Owing to the small number of toothed wheels for driving the cylinder and the bed, and more particularly owing to the direct connection of the form bed during the printing stroke with the revolving impression cylinder through the toothed segments I4 and the racks I5, disagreements in the development of these two members during the printing operation as a whole are precluded, so that even after lengthy operation no register differences arise.

The apparatus according to the invention may of course also be employed in printing presses in which the taking over of the sheet is not effected at the upper edge of the impression cylinder, as in the example of construction illustrated, but at its lower edge.

Furthermore the apparatus also admits of being employed in cylinder printing presses in which the form bed moves in a vertical direction.

What I claim as new is:--

1. In a cylinder printing press, the combination of a printing cylinder continuously rotating at uniform speed in the same direction, and a reciprocating form bed, said impression cylinder being reduced in diameter while retaining the arcuate length of the impression receiving segment as necessitated by the size of the sheet to be printed in such manner that the impression cylinder during the impression stroke of the said form bed is turned through a greater angle than during the return stroke of the form bed, a crank drive for reciprocating the form bed, and means for actuating the crank drive in such a manner that the crank in that period in which the impression cylinder travels through the greater angle passes through one-half revolution at reduced speed while the crank in that period in which the printing cylinder travels through the smaller angle makes a half revolution at accelerated speed.

2. In a cylinder printing press, the combination of an impression cylinder rotating continuously in the same direction at uniform speed, and a reciprocating form bed, said impression cylinder being reduced in diameter while retaining an arcuate length of the impression receiving segment as determined by the size of the sheet to be printed, so that the printing cylinder during the impression stroke of the form bed is rotated through a greater angle than during the return stroke of the form bed, a crank drive for V is a gear reciprocated by the crank drive,"a rack barlmountedon the form bed into which said last named gear engages, another rack bar slida'bly disposed in the frame ofthe press and alsoyengaged by said last named 'geanand means for shifting the lastnamed rack bar during the ro-' tation of the crank. V r

V 3. Ina cylinder printingpress thecombinak" tion of an impression cylinder and a reciprocating :form bed, said impression cylinder being reduced in diameter while retaining an 'arcuate-lengthof thefimpression receiving segment as determined ,by the size'of the sheet to, be printed, so that the impression cylinder during the impression stroke of the formbed iscrotatedthrough'a greater 7 angle than during the return stroke'of the :form bed; a drive gearing for continuously rotating said impression cylinder at uniform speed in -the same direction and for reciprocating saidiorrm and being arranged in such a manner that zone of said toothed :gears, which actuates said form bed, in 7 that period in ,which the impression cylinder travels through, the greater angle passes through one half revolution at reduced speed bed, said drive gearing comprising'toothed' gears V while said toothed-gearin that period's-in which the impression cylinder travels through the .smaller I angle makes a half revolution at accelerated speed. a

RUDQLF srftissr, 

